Remote lock/unlock not working
 

I got 2 keys with my car. One of them looks pretty beat up - obviously that is the one the previous owner was using a lot. The other looks slightly less well used.

The beat up key - it starts the car, locks/unlocks the doors by putting the key into the door lock and turning but none of the buttons on the key work.

The less beat up key - starts the car AND the remote lock/unlock work great.

“Must be a busted battery” I thought. Took apart the key, looks like it’d been open before (bad sign). I got it open, used my multimeter to measure the battery voltage - reads 3.0 (second bad sign). I decided to replace the battery anyway at that point since I had the thing open so I went ahead and desoldered the old battery and soldered the new VL2020 battery on there.

Went out to the car - still no go. Pressing buttons on the key has no reaction. But my other key definitely works.

Is there some sort of pairing that needs to be done to make this work?

Car is a 2005 4.8is

Sounds like it needs to be paired. I lost a key and had to go to the stealer to get a new one. Key from the parts counter only worked like your "less beat up key" had to go to the service counter for them to pair it. Took 5 min, should be done for free.

Syncing the keys to the car is free if you do it yourself, it takes a couple of minutes BUT you MUST do all keys in the same session. Any key not included will no longer work (remote operation only - it'll still manually unlock and start the car).

Make sure all keys are charged before performing the sync operation.

https://www.bimmernav.com/images/codekey.jpg

you can also send your key to the GM5 repair guy and he can fix it

True that - but you still have the re-sync all the keys when it comes back from the repair guy. :D

Which position is KL-R? Is that with the A/C panel on or without?

From Quicksilver on the e38 board:

* O = off
* KL 15 (terminal 15) or "run bus" (ignition switch run position) = ignition position 1
* KL 30 (terminal 30) or "battery bus" (hot at all times) = ignition position 2
* KL R (accessory bus) = ignition position 2
* KL 50 (terminal 50) or "start bus" (ignition start position) = ignition position 3 (start)

Ok, looks like the key is dead. I replaced the battery, confirmed good voltage at terminals on the circut board (ironically I had 3v with the old battery and 2.9 with the new) but the key will not sync with the car. I confirmed I am carrying out the sync process correctly by re-syncing my working key with the system.

Where do I find this gm5 repair guy?

Here...

https://www.bmwgm5.com/key_repair.htm

I have to come down on my self on this one...this information is INCORRECT! This must have been an old thread over on e38 bimmerboard. I have KL R & KL 15 switched around in regards to their ignition position as you turn the key in the quote above. :(



The correct terminal (ignition positions are listed below):



KL O= Off
KL R = ignition position 1
KL 15 = ignition position 2
KL 50 = engine start position
KL 30 = key position goes to after start

If you tried to reinitialize the remote keys and turned to ignition position 2...try it again, this time turning to ignition position 1 (KL R).


Some other tips:

• Make sure ALL doors are CLOSED
• Make sure ALL doors are UNLOCKED
• Only insert the 1st key into the ignition...start the 2nd remote on STEP 3 where you start pressing the buttons (just as stated in STEP 6)